Among cardiac patients and critically ill populations, hyperglycemia is associated with increased mortality. Following cardiac surgery specifically, wound infections and other morbidities are increased among patients having diabetes or uncontrolled hyperglycemia. Strict glycemic control during the perioperative time period can reduce morbidities and mortality. Some of the most striking outcome results have been achieved with the user of perioperative intravenous insulin infusions. Outside of the intensive care unit, and after the third postoperative day in the hospital, or during subsequent outpatient follow-up after heart surgery, concerning the importance of glycemic control or the methods used to achieve control, there are less population-specific data than during the earlier timeframe immediately following surgery in relation to outcomes. Nevertheless, it is reasonable to apply hospital and outpatient glycemic standards for glycemic control that have been advocated for hospitalized and general populations.
The default order for a busy medical practitioner at the time of transition from intravenous insulin infusion, if an institutional standardized sliding scale exists, is likely to be a “sliding scale”. Sliding scale refers to an algorithm that assigns blood glucose test times and short- or rapid-acting insulin, in preassigned doses that often are arbitrarily determined without consideration for the insulin sensitivity of the patient to be administered at predetermined times according to the severity of the hyperglycemia, without consideration for carbohydrate exposure, and to be used without concomitant orders for intermediate- or long-acting insulin or scheduled mealtime insulin.
Use of sliding scale insulin as monotherapy results in poor control. Hyperglycemia and sometimes ketoacidosis result from omission of scheduled insulin. Sliding scale insulin doses, given reactively after development of hyperglycemia, are implicated in the causation of hospital hypoglycemia, especially in the presence of renal failure. Accordingly, there exists a long-felt need for improved methods and systems for determining an intravenous insulin infusion rate to correct hyperglycemia of a patient, to maintain euglycemia of a patient, and to prevent hypoglycemia of a patient.